DVB-T数字电视地面广播之移动接收

欧洲的DVB-T标准最初是为便携和固定接收而设计,其技术参数如载波数量、调制方式、卷积编码率和保护间隔等可调,可提供许多传输模式。实验室测试和现场试验已证明其中一些传输模式适合于地面移动接收。本文从数字移动电视网络和接收终端两方面来介绍影响DVB-T移动接收的因素。     

移动数字电视接收与DVB-H

从接收端的角度出发分析了DVB-H标准在功耗、移动性和服务质量方面的技术改进,并介绍了DVB-H最新进展,对未来移动数字电视的发展提出了自己的观点.     

数字电视地面传输标准及其移动接收应用

本文介绍了数字电视及数字电视地面传输标准DTMB,探讨了DTMB采用的关键技术以及移动接收技术的发展前景.     

多媒体移动接收与DVB-H的发展

DVB-H是数字视频广播(DVB)组织为通过地面数字广播网络向便携/手持终端提供移动多媒体业务所制订的最新标准.本文分析并介绍了3G、WLAN和DVB-H在多媒体移动接收领域各自的技术特点和最新进展,对未来多媒体移动接收领域的发展提出了自己的观点.     

移动通信基站对C波段卫星信号接收的影响

卫星信号的传输,不可避免地会受到各种电磁波干扰,通过对宁波电视台C波段卫星信号被干扰情况的分析、查找,针对移动通信基站对C波段卫星电视信号的干扰进行分析,并提出解决办法。     

4G移动网络在高清电视新闻直播中的应用展望

数字电视进入高清时代,移动通信的发展即将进入4G时代。本文阐述了4G无线传输系统中各种关键技术（诸如MIMO天线、OFDM、LDPC等）的基本概念和基本原理,并从技术的角度探讨了利用4G网络电视新闻直播系统的设计思路,分析了4G网络在现代电视新闻直播中的优势。     

Adaptive Hybrid Beamformer for Mobile Reception of ATSC DTV

An adaptive hybrid beamformer is proposed to improve the reception performance of the advanced television system committee (ATSC) digital television (DTV) in a mobile environment. Dynamic multipaths and Doppler shifts severely degrade the reception performance of the ATSC DTV receiver. Accordingly, a hybrid beamformer, called a Capon and least mean square (CLMS) beamformer, is presented that uses direction of arrival (DOA) information and the least mean square (LMS) beamforming algorithm. The proposed CLMS algorithm efficiently removes dynamic multipaths and compensates for the phase distortion caused by Doppler shifts in mobile receivers. When the CLMS beamformer has an insufficient degree of freedom (DOF), the subsequent use of an equalizer removes any residual multipath effects, thereby significantly improving the performance of DTV receivers. The performances of the proposed CLMS, Capon, and LMS beamformers are compared based on computer simulations. In addition, the overall performance of the CLMS beamformer followed by an equalizer is also considered.     

HDTV制式与HDTV

本文对世界三大HDTV制式——日本MUSE、西欧HD-MAC和美国多种与NTSC兼容共存HDTV制式中具有代表性的制式,从原理和技术性能上进行了讨论比较,其中主要有MUSE、N-MUSE、NCM-6、NCM-9、D-MAC/packet、D_2-MAC/packet、HDS/NA、HDS/NA-6、SC-HDTV等。并根据今后HDTV发展方向给出了目前国际上与现有电视制式兼容共存的几种途径,以及判断一种HDTV制式优劣的标准。     

下一代移动网络中非连续接收机制对移动互联网业务性能影响分析

移动互联网业务的发展引发了大量需要终端与网络间进行频繁交互的业务,产生了终端能量和无线信令资源消耗过度的问题。结合3GPP标准定义的下一代移动网络非连续接收(discontinuous reception,DRX)机制,从终端能耗、数据包延时、空口资源开销等角度出发,分析了DRX机制对典型移动互联网业务的网络性能影响,并对DRX机制的参数配置提出了优化建议。     

地面国标C=3780固定接收业务中嵌入C=1移动接收业务

在发射功率不变时,利用:1)地面数字电视的固定接收可使用增益高达15 dBi的方向性天线;2)地面国标C=1的现场测试C/N门限值与C=3 780相比要低约3.5 dB;探讨在C=3 780固定接收业务中嵌入C=1移动接收业务的可行性.     

移动接收卫星电视的天线自动跟踪系统

本文利用了卫星姿态测量和导弹制导技术中的陀螺传感器、电子罗盘、GPS模块等的组合，对行驶中的车载卫星电视天线接收方向的变化，作出敏感的反应，然后通过微处理器进行处理后送伺服驱动系统，来控制伺服电动机转动天线，使得天线的中心轴在汽车行驶过程中始终对准卫星。并采取适当的方法对长时间行驶产生的累积误差进行修正，确保移动接收卫星电视正常工作。这样的设计广泛地应用在任何载体上（包括汽车、火车、轮船、飞机）。     

ATSC DTV的移动接收技术

文章从改进ATSC标准、引进自适应阵列天线技术和提出快速均衡算法三方面论述了提高ATSC DTV移动接收性能的方法.通过仿真验证了这些方法的有效性.     

移动广播电视接收的阴影区覆盖措施

在大连手持移动广播电视播出实践的基础上,提出了几种可行的移动广播电视接收阴影区补充覆盖手段,重点分析了用有线传输信号无线转发和泄漏同轴电缆转发.     

加快我国高清电视、数字电影和移动多媒体广播电视发展——国家广电总张海涛副长在BIRTV2008主题报告会上的讲话摘要

我国已建成世界上覆盖人口最多,无线、有线、卫星、互联网等多种技术手段并用,中央与地方、城市与农村、国内与国外并重的规模庞大的广播影视网络.如何保证全系统安全运行,如何完善广播影视公共服务体系,如何尽快实现数字化转换,构建传输快捷、覆盖广泛,技术先进的广播影视传播体系,是我们全国广电系统当前和今后一段时期的重要任务和神圣使命.     

Digital Broadcasting Television Channel Measurements and Characterization for SIMO Mobile Reception

This paper presents propagation measurement results in the UHF Digital Television (DTV) band using an ATSC DTV signal as a channel sounding signal to investigate the characteristics of a wideband single-input multiple-output (SIMO) under mobile reception conditions. A series of DTV dual channel signal measurements were conducted in the Ottawa region to characterize the transmission of ATSC 8-VSB signals under different propagation environments. A dual channel receiver was used to record SIMO signals: these were used to provide channel impulse response estimates. From the recorded time-varying impulse responses and their correlation functions, average power delay profiles, scattering functions were computed to analyse the joint spatial fluctuations of the received signals. The DTV channel characterization study is aimed at broadcast system designers involved in data transmission of terrestrial digital television signals over mobile channels with diversity reception     

实现数字电影的"胶片感"——数字电影《冬至》摄影创作体会

电影故事片《冬至》,是2002年12月初经电影局核发单片许可证,由世纪英雄电影投资有限公司和万基集团北京万基文化传播有限公司联合投资出品的。从2002年12月29号开始开机到2003年1月30号停机,拍摄周期约30天。该片由田壮壮任监制,谢东任导演和编剧,吴樵担任摄影。主要演员有秦海璐、许亚军和胡靖钒,总投资180万元人民     

Outage Analysis due to Multipath Mobile Radio Reception with Poisson Multiphath Arriva

The multipath self-interference (MSI) with Poisson multipath arrival is investigated in this paper. A number of scenarios are built around the statistical characterization of the magnitude of desired signal and the composite interfering signals, namely, Rayleigh/Rayleigh-Poisson, Rayleigh/Nakagami-Poisson, Nakagami/Nakagami-Poisson, and Rice/Nakagami-Poisson. It is shown that MSI can be statistically characterized in a similar manner as impulse or shot noise. The probability density function of the power ratio of desired to interfering signals is derived which is used to find the expressions for system outrage probability for the considered scenarios.     

应用于DBS移动接收中的5位数字移相器——低成本、Ku波段

提出了一种应用于DBS移动接收中的5位数字移相器的设计方案,并通过实验验证了其实际性能。该移相器采用加载线型和反射型移相原理,首先应用ADS软件进行设计仿真;仿真结果显示该移相器具有频带内高移相精度、低插入损耗和低VSWR等性能,符合设计要求。最后使用Agilent矢量网络分析仪对实物进行测试,进而验证了设计方案的正确性。     

HDTV standards

An overview of relevant International Radio Consultative Committee (CCIR) activities in the area of high-definition television (HDTV) standardization is presented. The status of the CCIR standards with respect to chromaticity and signal format, picture characteristics, picture scanning characteristic, and analog and digital representation is discussed. It is concluded that the achievement of a single unambiguous parameter set requiring no quality impairing conversions in international program exchange remains doubtful